NASA scientist creates a video of a liquid sand hot tub

A former NASA engineer has created a hot tub with a difference, filled with liquid sand that acts the same way as water, allowing him to float and splash around.

Mark Rober, 37, from Orange County, California, is known for his quirky science based videos on YouTube.

And for his latest post, he decided to customize a hot tub so he could experience the sensation of floating in liquid sand, known in science as a fluidized air bed.

Weightless: Mark Rober, 37, from Orange County, California has created a YouTube video where he appears to float in a hot tub filled with sand

Learning zone: The former NASA scientist is known for posting quirky science videos on YouTube

Experiment: During the video, Mark reveals how he created ‘liquified sand’ using an old hot tub, copper pipes and pressurized air

‘I am sitting in a hot tub filled to the brim with solid sand. This is one of the coolest things ever,’ Mark told the camera as he sat in his creation.

‘If you take a tub of sand like this and add air in just the right way, it basically becomes a liquified soup.’

Explaining the the theory behind this, he said: ‘In science this is known as a fluidized air bed. It’s used in industrial applications such as powder coat painting or in grain silos to make sure the grain flows smoothly to the outlet.’

Describing the effect, which used pressurized air to put the sand in motion, he added: ‘With the air on, the surface is frictionless, like an air hockey table. And then when you cut off the air, it freezes everything exactly where it’s at.’

Mark then explained that because he was curious to see what it would feel like to be fully immersed in something like that, he made a hot tub sized version.

However, putting the theory into practice proved slightly more difficult and unable to find a formula online, it took him 25 failed versions before he arrived at a design that worked.

While not as easy accessible as water, Rober says creating liquid sand is pretty simple to do if you have the right equipment.

The big sand theory: Mark revealed the scientific theory behind his invention, explaining it is known as a ‘fluidized air bed’

Trial and error: The scientist tried 25 different methods before figuring out the correct way to create liquid sand

Big difference: Mark was compelled to create a hot tub version of this experiment so he could experience how it feels to float in sand

In the video, he then showed how he and his friends constructed the hot tub using copper pipes and a pressurized air canister.

And the result is oddly mesmerizing to watch as those in the liquid sand seem to float and splash around like they would in water.

However, Mark revealed that when the air is stopped from flowing into the sand, he is locked in, telling the camera, ‘it’s like a weighted blanket on every surface of your body’.

He then showed how weightless the sand really was when pumped full of air by showing various balls being slammed into the sand and then bouncing back to the surface with ease.

However, the best part of the video is when his three nephews arrived to his house and Mark surprised them with the liquid sand hot tub.

Sitting hidden inside the hot tub, Mark popped out from under a giant plant pot as the boys peered into the hot tub, not knowing how to react to the sand seemingly turning to liquid as the air was pumped in.